The granary for cereals, Gorongosa Type

Transcription

1 The granary for cereals, Gorongosa Type By: Manfred Schug, Advisor for Agrarian Technologies, INGC, Mozambique. 1. Introduction The granary for cereals, Gorongosa Type (GGT) was developed between 1997 and 2002 under the Sofala Integrated Program for Food Security of the Provincial Directorate for Agriculture (DPA) and GTZ. This granary is the experimental result from different variants and prototypes of granaries and the creativity of local technicians and peasants from District Direction of Agriculture and Rural Development (DDADR) of Gorongosa. The target public of this technology are the smallholder farmers and families. The development and introduction of GGT aimed to provide to the peasant s families appropriate and economically viable grain conservation technology, so that proper cereal (and other grains) storage is achieved for both familiar consumption and commercialization. The initial concept, focused on the exclusive use of local material, was gradually abandoned in favor of more durable, functional and low cost model, composed by local as well as conventional materials. Although by the time of GGT implementation, there was no incidence of grain large borer (Prostephanus truncatus) in the Province of Sofala, the granary was conceived to be P. truncatus-proof. During the validation phase, the granary was continuously adapted until the dissemination phase ( ) at Gorongosa and Cheringoma Districts. In 200 the granary was disseminated in all Districts of Sofala Province and in the neighboring Provinces. GGT is appropriated for the storage of cereals and other grains in all Mozambican regions. The estimated number of granaries constructed is around 400. This modest figure seems to be linked to the centralized dissemination strategy rather than to the technical or economical viability of GGT. In order to better exploit the granary potential for the improvement of food security and familiy income, an adjustment of the dissemination strategy is recommended. It is important that all decision makers, at all levels, have a precise idea about the cost-benefits of GGT for individual families, in particular, as well as for the rural development, in general. 1

2 Fig. 2.: Position and dimensions of iron rods Diameter of base and cover (D) Length of circular frame (AC) Length of transversal frames (AT) Thickness of base s poles Thickness of cover s poles cm 480 cm 145 cm 8 mm mm Filling hatch 35 cm x 45 cm

3 2. Technical description and construction costs 2.1. Technical specifications for a Granary Gorogonsa Type with the capacity of 1 ton The technical specifications for the standard granary are the following: Capacity: 1000 kg of grain (55 cans of maize with a capacity of 20 liters) Masonry base (circle-shaped): 7 cm thickness, 120 cm diameter Masonry cover (circle-shaped): cm thickness, 120 cm diameter Cylindrical wall of sun-dried trapezoidal-shaped mud bricks (180 cm height) with inside and outside mud-plastered walls Mud-plastered base (5 cm) in order to prevent condensation Filling height: 10 cm Filling and maintenance opening (35 cm x 50 cm), lockable Cemented discharge window (15 cm x 10 cm), lockable Protection porch Fig. 1: The Granary Gorongosa Type Granary Gorongosa Type Masonry cover with lid (35 cm x 45 cm) and handle Cylindrical wall (185 cm) of sundried trapezoidal-shaped mud bricks Inside and outside mud-plastered walls Wire rings (3 mm ø) inserted on the walls at 30, 0 and 90 cm high Cemented discharge window (15 cm x 10 cm) Masonry base on top of field stones Obs: The size of the granary is variable, adjustable to the user needs. 2

4 2.2. Granary Gorongosa Type (GGT) dimensions and material needs Tables 1 to 4 present the granaries dimensions and material needs for the construction of GGT s. Figure 2 shows the position and dimensions of iron rods. Table 1: Capacity of Granaries External base diameter (cm) Wall thickness (cm) Internal diameter (cm) Internal height (cm) Gross internal volume (liters) Filling height (cm) Usable Volume (liters) Capacity (20 liter cans) Capacity (kg of maize) , , *) , , , , Table 2: Dimensions, weight and cement needs for the granary s base Base diameter (cm) *) Base thickness (cm) Base volume (liters) Cement (kg), trace 1:**), Base weight (kg) (!) 423 (!) *) Standard model (capacity for 1000 kg of maize) **) 1 part cement: 2 parts clean sand : 4 parts medium and fine crushed stone Obs: Parts correspond to equal volume units. 3

5 Table 3: Dimensions, weight and cement needs for the granary s cover Cover diameter (cm) Cover thickness (cm) Cover volume (liters), excl the lid of the filling opening (35 cm x 50 cm) Volume of lid (liters) Cover volume + lid (liters) Cement needed for the cover + lid (kg), trace 1: Weight of cover, excl. lid (kg) Table 4: Summary of cement needs for the granary s base, cover and discharge window Base diameter (cm) Base, trace 1:, (kg) Cover + lid, trace 1:, (kg) Discharge window, incl. weir, trace 1:4, (kg) Total (kg) Obs: One cement bag of 50 kg is enough to build up a granary with a diameter of 120 cm (capacity for 1000 kg maize) 4

6 2.3 Construction costs (200) a) Materials from outside (non-local) 1 bag of cement USD m rough iron rods (mm) USD m smooth iron rods ( mm) USD 1.3 0,8 m smooth iron rods (10 mm) USD m burned iron wire USD m galvanized wire (3 mm) USD 1. 2 pad-locks (filling opening and discharge window) USD poles with 3 m length for the porch USD 5.7 Transport USD 4.0 Total USD 32.5 b) Specialized workers Granary s builder USD 1.3 c) Granary s owner contribution Collect local materials Make mud bricks Help the granary s builder Build the porch Total contribution from Granary s owner USD 20.3 Total cost of granary and porch (total construction costs + total granary s owner contribution) USD 9.1*) *) since the contributions from the granary s owner are not paid in cash, the real monetary value is $ 9.1 $ 20.3 USD 48.8

7 3. Grain treatment Since contaminations with insects, eggs, larvae, etc may occur during the filling process, grain treatment is absolutely required. The use of phostoxin (aluminum phosphide) is the recommended treatment. Phostoxin is available in tablets that release a toxic gas (phosphine) when exposed to air humidity. Special care must be taken since phosphine is also harmful to men and animals. Depending on the temperature and humidity the chemical reaction of phostoxin, and thus phosphine emission, may take 3-5 days, the necessary time to penetrate inside the grains and kill insects, eggs or larvae. Dosage should be used according to the instructions provided by the manufacturer. Fig. 3: Granary with porch Phostoxin is applied through a bamboo tube with holes along its entire length that is placed in the center of the granary. Once the granary is filled, the recommended amount of phostoxin pills are introduced through the upper part of the bamboo tube. The bamboo tube helps the penetration of gas inside the grains, avoiding direct contact with it. The filling opening and the discharge window are then sealed with mud. After the treatment, the mud-plastered granary s walls (inside and outside) do work as physical barriers to avoid new contaminations with insects and rat attacks. Photo: Mario Norman, PRODER Sofala The grain treatment with Pyrimiphos-metilo (Actellic) is not recommended for hermetic granaries, like the Granary Gorongosa Type, not only because it is appropriated for non-hermetic grain storage (like storage in bags), but also because it is 9-15 times more expensive than phostoxin (1 ton grain treatment with phostoxin = USD 0.4; 1 ton with Actellic = USD 3.7.1). 7

8 4. Condensation One of the major advantages of the Granary Gorongosa Type (GGT) is that its mud-plastered walls can absorb the cereal s humidity and conduct it outside, avoiding condensation inside the granary. If condensation occurs, it will be localized in the walls, being quickly absorbed by the dry mud. For long term storage, the maximum humidity content in the grains should not exceed 13%. This value is applicable for white maize, sorghum and rice. Values higher than 13 %, may result in fungal contaminations which makes the grain not appropriated for human consumption. The humidity limit of 13% is established for an environment with a relative humidity (RH) of 5-70 % and temperatures between 20 ºC and 30 ºC. In the coastal zone of Mozambique, the relative humidity is frequently higher than 5 70 % during the period of cereal storage. Table 5 refers to the Rate of Equilibrium Humidity for a temperature range of 20º and 30ºC and table presents the historical climate data from Gorongosa. Table 5: Rate of equilibrium humidity for a temperature range of 20 ºC and 30 ºC Product Rate of equilibrium humidity for a relative humidity of: 50% 0% 70% 80% White maize Sorghum Rice Source: GTZ / J.Gwinner, R. Harnisch, O.Mueck: Manual sobre a Prevenção das Perdas de Grãos depois da Colheita (Manual for Prevention of Grain Losses after Harvesting) Table : Historical climat data from Gorongosa Meteorological Station Coordinates: 34º 04 E, 18º 41 S, Altitute 300 m, Period: 31 years Jan Feb Mar Abr. May Jun Jul Aug Sep Oct Nov Dec Annual Precipitation (mm) Evapotranspiration (mm) Average Temp (Cº) Average Temp max (Cº) Average Temp min (Cº) Rel. Humidity (%) Source: Kassam et al. (1981), cited by: J.M Mafalacusser e M.R. Marques (2000): INIA-DTA / GTZ PRODER: O Potencial dos Recursos Agrários do Distrito de Gorongosa (The Potential of Agricultural Resources in the District of Gorongosa) 8

9 5. Fire-Proof Granary Cereals stored in the Granary Gorongosa type are also protected against fire because none of the materials used for the construction are flammable.. Number and size of granaries The great majority of smallholder farmers grow ha of cereals and under normal climate conditions a granary s capacity of kg is not enough to store the grains for consumption and commercialization. In many zones, families produce at least two cereals species: maize and sorghum. Additionally the recommended amount of stored grain is the double of the family needs. This will guarantee food security of the family in case the production is compromised in the following year by (a)biotic factors. This way, the food security reserve can be stored over a period of 7-9 months and, under normal conditions, can be sold out at higher prices than at harvest time. Therefore, most families need at least two granaries. If an average family adopts the System of Conservation Agricultural the average number of granaries will grow from 2 to 3. The normal capacity of the granary is 1000 kg of maize, corresponding to 55 cans of 20 litres. This granary has diameter of 120 cm and an internal height of 180 cm. It is not recommended to fill the granary above 10 cm, so that 20 cm are free for the periodical control of the content. Since each family produces different cereals (and other grains), the space needs for storage and the dimensions of the granaries are variable. According to each family needs, the Granary Gorogosa Type can be built of different sizes, with diameters ranging from 100 cm to 150 cm and different heights. (see table 1). An external diameter of 100 cm with a corresponding internal diameter of 7 cm is the minimum size. A narrower granary would hamper wall plastering, cleaning and maintenance. A diameter of 150 cm is the maximum recommended, due to the weight of the base (423 kg) and cover (333 kg) and the resulting difficulties of managing heavy components. 9

10 7. Economical aspects of maize storage at the familiar level The price of 1000 kg of maize (= 55 cans of 20 litres) sold 1-2 months after the harvesting is USD (= USD 0,089/kg or USD 1,2 / can). The following table shows the prices of the same quantity of maize stored for a period of 7 to 9 months, depending on the selling price by that time: Price of one can of maize (USD) Value of a maize granary of 1000 kg = 55 cans) (USD) Value increase after harvesting (base USD 89.43) times times times times If a producer sells one can of stored maize at USD 3.25, the price has doubled when compared to the price of maize sold 1-2 months after harvesting (USD versus USD 89.43); if the price of one can is 4.07, the producer gets USD , which is 2.5 times more than that sold after harvesting. Considering a selling price of USD 4.07/can: - Total income: + USD Cost of granary: - USD Cost of grain treatment: - USD 1.22 The producer has a liquid income of USD Under these circumstances the granary is amortized already during the first year. It should be noted that the granary has a minimum life time of at least 20 years, with minimal maintenance costs. 7.1 Macro-economics considerations Cereal storage in Mozambique is a service that brings high incomes. Normally this kind of services is provided by warehouses from urban centers. With the availability of granaries, like the Gorongosa Type, smallholders have the possibility to access markets and to exploit a source of non-traditional income. As mentioned before, 1000 Kg of stored maize results at least in a duplication of the commercial value of the product. Thus, in order to enhance familiar food security and incomes, it is recommended: a) The adoption of Conservation Agriculture b) The conservation of cereals and other grains in appropriate granaries 10

11 c) The storage of double amount of cereals (or other grains) needs, so that it can compensate for low yield the following season or be sold in the following year if yields are normal d) To take also in account the needs for animals, beverages, etc With an average of 2 granaries and a safe conservation technology, each smallholder family has the possibility to avoid cereal shortage during the months preceding the next harvesting and to improve the family s income. This is an excellent strategy to reduce poverty in rural areas. 8. Strategy for the promotion of cereal s granaries 8.1 Past experiences Although the Granary Gorongosa Type (GGT) was considered technically and economically appropriated for smallholder farmers, its dissemination is far from what was desired. One of the weaknesses of the granary s program in past years was the centralization of granary s construction and promotion, usually under the responsibility of the District Directorate of Agriculture and Rural Development (DDADR) and/or their partners. Thus, at the district level the number of granaries was far insufficient and dependent upon activity plans of the responsible institution. The putative beneficiaries of granaries, normally did have a scarce knowledge about the benefits and advantages, and simply adopt the technology upon recommendation of DDADR technicians / extensionists. The trained granary builder got the execution plan from DDADR, with the indication of the number of granaries, areas and selected families (by technicians/ extensionists). The builder received the necessary instruments and materials and after a certain number of granaries were constructed he was paid for the services and he considered his job done. Because the granary builders often did not have any knowledge about the grain conservation techniques, and often the technicians / extensionists couldn t always follow the implementation plan, not all farmers did receive the necessary instructions for the correct use of the granary after the granary s construction, which resulted in some bad experiences at the expenses of the granary s owners and a negative reputation for the GGT. 11

12 7.2 New strategy: The Granary Promoter Better technology divulgation has been a key to success. The revised strategy includes the integration of Granary s Promoters or Cereal Conservation Promoters. Promoters are properly trained for granary construction and identification of clients in a proactive way, informing them about the advantages and characteristics of the granary, costs and benefits and owner s contribution for granary construction. Moreover, Promoters receive appropriated training in techniques for grain conservation, assisting the clients in proper grain storage practices after the construction of the granary. For Cereal Conservation Promoters, granaries construction and grain conservation services are income-producing activities, under coordination of the technician / extensionist and with the support of DDADR. The income level depends on the degree of technology dissemination, number and quality of granaries and further assistance for grain conservation. Granaries Promoter must have the following competences: a) To understand the basic principles for the calculation of the granary s costs and benefits b) To know the organisms (insects, rodents, fungi etc.) that may cause losses during grain conservation under inappropriate conditions c) To be able to assist and supervise the granary s owner for the preparation of the granary s construction materials and protection structure (porch) d) To have experience and knowledge on the construction of high quality granaries e) To supervise and advice the granaries owners for the correct use of biological and chemicals repellents for grain conservation, avoiding grain losses and harmfulness for the consumers f) To keep close links with the technician/extensionist from DDADR The technician/extensionist must be competent in a), b) and e). Incentives for Granaries Promoters : a) Gratification for granary construction, paid by granary s owner b) Incentive from DDADR or its partners c) Fees for assistance in grain conservation / protection and granary s maintenance, paid by granary owners d) Periodical training on post-harvest conservation (and eventually processing) of food products 12

13 8.3 Spatial Extension of Granaries Promotion Experience has shown that granary owners are under pressure from the wider family and neighbors that claim for grain help during the scarce months (usually from October onwards). In order to avoid such situation, an all-village or all-family approach is strongly recommended in order to take away some of the pressure from the individual peasant Credit for the first year of storage Although cereal storage is a highly rentable activity, its implementation has some obstacles, especially during the first year. Many families sell their maize immediately after harvesting at a low price in order to cope with current or extraordinary expenses. The sale of grain is also a strategy to avoid losses due to insects and other pests. One of the greatest difficulties is the generation of income for the current expenses during the first 7-9 months of storage. One of the possibilities to overcome this problem is the creation of a fund for a bridge loan during the first year for the families who have build a granary. A credit of USD for the construction and filling of a granary is recommended. USD 120 corresponds approximately to the external costs for granary s construction (USD 50) + the commercial value of grain 1-2 months after harvesting (USD 90). The income generated by selling 7-9 months stored grain (USD ) would cover the credit and still bring some additional net income to the family. 13